1. Field of the Invention
The present invention relates to a piping structure, an existing pipe cutting method and a fluid supply suspension free method.
2. Description of the Related Art
Existing running fluid pipes such as water pipes may possibly contain dirt or foreign substances such as sands, rust powders and metallic powders. Catching or collecting those foreign substances may therefore be indispensable. Such foreign substances have thus been collected and removed up until now. A known dirt collector is provided for example with a dirt reservoir expanding radially from the running fluid pipe body, the dirt reservoir having therein a meshed filter located at right angles to the axis of pipe (e.g., Japanese Patent Laid-open Pub. No. Hei7-136420).
Existing pipe lines have however often included sites free from such dirt collectors.
It is therefore the object of the present invention to provide a piping structure and so forth capable of collecting dirt or foreign substances without any suspension of the supply of a fluid such as water or oil.
In order to achieve the above object, according to a first aspect of the present invention there is provided a piping structure comprising an existing pipe and a seal-up housing. The existing pipe has a collection opening formed in the bottom thereof. The seal-up housing comprises two or more housing parts which are segmented in the circumferential direction of the existing pipe. The seal-up housing encloses a part of the existing pipe including the collection opening. One of the housing parts is formed with a collection space and a drain port. The collection space is adapted to collect dirt or foreign substances through the collection opening. The drain port communicates with the collection space, for discharging the dirt or foreign substances stored in the collection space.
In the piping structure of the present invention, the collection opening is most preferably an elongated cut groove which is formed in the axial direction of the existing pipe.
In order to form the cut groove, according to a second aspect of the present invention there is provided a method of cutting an existing pipe comprising an assembling step and a cutting step.
In the assembling step, the existing pipe is partially enclosed in a hermetically sealed manner by a seal-up housing consisting of a plurality of housing parts which are segmented in the circumferential direction of the existing pipe. A cutting unit having a cutting tool is mounted on the seal-up housing.
In the cutting step, the cutting tool is turned by the power of a prime mover so that the cutting tool can perform a cutting action for cutting the bottom of the existing pipe. The cutting step includes allowing a radial cut of the cutting tool into the existing pipe while turning the cutting tool to impart the cutting action to the same and includes displacing the seal-up housing in the axial direction of the existing pipe simultaneously with the cutting action. By imparting a feed action to the cutting tool through the axial movement of the seal-up housing in this manner, the existing pipe is cut by means of the cutting tool without creating any cut-off sections. The cutting tool thus forms an elongated rectilinear groove in the bottom of the existing pipe in the axial direction thereof.
In order to obtain the piping structure of the present invention, according to a third aspect of the present invention there is provided a fluid supply suspension-free method comprising an assembling step and a drilling step.
In the assembling step, an existing pipe is partially enclosed by a seal-up housing consisting of a plurality of housing parts which are segmented in the circumferential direction of the existing pipe. The seal-up housing is provided with a collection space and a drain port. The collection space is adapted to collect the dirt or foreign substances through a collection opening formed in the bottom of the existing pipe. The drain port is provided for discharging the dirt or foreign substances stored in the collection space.
In the drilling step, the collection opening is formed in the bottom of the existing pipe lying within the seal-up housing without any suspension of the fluid supply.
Any dirt or foreign substances residing within the existing pipe will migrate through the collection opening down into the collection space and collected therein.
According to a fourth aspect of the present invention there is provided a fluid supply suspension-free method preferably comprising an assembling step, a cutting step and a tool removal step which follow.
The operator first prepares a seal-up housing comprising two or more housing parts which are segmented in the circumferential direction of an existing pipe. One of the housing parts is previously provided with a collection space and a branching portion. The collection space is configured to be suited to collect dirt or foreign substances through a rectilinear groove formed in the bottom of the existing pipe. The branching portion is provided for allowing a cutting tool to advance or retreat (i.e., to cut into the existing pipe in the radial direction thereof).
In the assembling step, the existing pipe is partially enclosed by the seal-up housing in a hermetically sealed manner. A cutting unit having a cutting tool is mounted on the seal-up housing by way of an operation valve.
In the cutting step, the cutting tool is turned by the power of a prime mover so that the cutting tool can perform a cutting action for cutting the bottom of the existing pipe. The cutting step includes allowing a radial cut of the cutting tool into the existing pipe while turning the cutting tool to impart to the same the cutting action and includes displacing the seal-up housing in the axial direction of the existing pipe simultaneously with the cutting action. By imparting a feed action to the cutting tool through the axial movement of the seal-up housing in this manner, the existing pipe is cut by means of the cutting tool without creating any cut-off sections. The cutting tool thus forms an elongated rectilinear groove in the bottom of the existing pipe in the axial direction thereof.
In the tool removal step, the cutting tool is withdrawn from the branching portion after formation of the rectilinear groove.
Any dirt or foreign substances residing within the existing pipe will migrate through the rectilinear groove down into the collection space and collected therein.
The present invention enables a dirt collection apparatus to be mounted on the existing pipe without requiring any suspension in the fluid supply. Furthermore, any large-scale work will not be needed since the collection opening is formed in the bottom of the existing pipe in place of cutting off the existing pipe.
In particular, the present invention provides the collection opening in the form of an axially substantially elongated opening such as the cut groove elongated in the axial direction of the existing pipe, thereby preventing any dirt or foreign substances from jumping across the substantially elongated opening, to consequently achieve a secure collection of the dirt or foreign substances.
In the present invention, the xe2x80x9cexisting pipexe2x80x9d refers to a pipe through which flows a fluid such as water or oil and which is often situated under the ground.
The term xe2x80x9cseal-upxe2x80x9d does not mean completely sealing, but means keeping watertightness to such an extent that a work can be done without any suspension of the fluid supply. Therefore, the xe2x80x9cseal-up housingxe2x80x9d refers to a housing having a pressure resistance enough to resist the pressure of the fluid flowing through the existing pipe and having a certain level of water stop ability.
As used herein, xe2x80x9cenclose something in a hermetically sealed mannerxe2x80x9d means sealing something to such an extent as not to hinder the cutting operation and so forth. For example, the drain port provided in the seal-up housing may remain opened during the cutting operation so that cutting chips can be discharged together with the fluid through the drain port.
The xe2x80x9ccutting toolxe2x80x9d for use in this method is preferably a milling-like tool whose tip surface and peripheral surface are each provided with a plurality of cutting edges.
In the event of cutting an existing pipe having a mortar lining formed on its inner surfaces, use is made preferably of a cutting tool provided with a multiplicity of hard metal chips or of a cutting tool having cutting edges made of grains of diamond.
In the present invention, xe2x80x9ccuttingxe2x80x9d means removing a part of the pipe wall through turns of the cutting edges. As used herein, the xe2x80x9ccutting actionxe2x80x9d means turning the cutting edges, whereas the xe2x80x9cfeed actionxe2x80x9d means moving the cutting tool to positions where virgin areas of the pipe wall can be cut in succession by the cutting tool.